Casco Viejo is an old city Bilbao actually. It is several streets on the other bank of the river. You can find here La Ribera market, New Square, Arriaga Thearter, Catherdral and old churches. Some of the streets are pedestrianized ones.

Everywhere you look there is history in the walls of the place and many pretty buildings to marvel at. The square is alive with tourists but you still get the old town vibe through the layout and traditional pinxos bars all around. We went during a fiesta so it was especially busy, including a hen party, so if you don’t like crowds trying using a restaurant or cafe outside of the main square

First trip to Bilbao. My wife and I loved it. This former industrial city has reinvented itself as a cultural, tourism, and knowledge industry center. The Casco Viejo -- loads of narrow medieval streets and alleys mostly filled with shops catering to tourists -- was interesting. But it was jammed. We found the rest of the city on the other side of the river to be equally if not more interesting: Gran Via, Guggenheim, the bridges, the streets around Abando metro stop to be as if not more interesting. The Mercado de la Ribera (the old covered market) is 1/2 traditional market with the stalls you'd expect. The other half is an essentially a huge tapas bar aired at tourists. You need to go, but once is sufficient. Tip #1: Be sure to buy the transit card (3 Euro) and put some money on it. The card is good on buses, the term, subway and the funiculars. It's a great bargain. Tip #2: Do not miss the Basque cheese cake. "Tarta de queso." You can buy it at just about any bakery or sandwich shop. It puts NY-style American cheesecake to shame. Tip #3: Any calories you consume in Spain do not count. You'll be walking enough to more than offset them.

Beautiful architecture and so many shops - but be aware of time of day for best experience. Shops and restaurants often close midday . Many little “plazas” to enjoy. Plaza Nueva has many places to sit and you can grab a variety of pintxos from several places. Bakeries, cafes, bistros, and bars line the street with several different shops with shoes, hats, clothes and even stationary.